The Unofficially Official Sub-Caliber/“Micro Bore” thread!

[Basher]

Thought this might be a fun topic I don’t often see discussed here, but how about a thread dedicated to sub-caliber (anything below .22) rifles?

I recently got bit by the .17 bug, and would honestly love a .20 as well though that may be awhile yet. I have a .17 Fireball and will be picking up a .17 Ackley Bee next week, but anything sub-cal would belong here no matter how obscure. Calhoon stuff, Ackley stuff, .10s, .12s, .14s, .17s, 19s, .20s bring it all!

To start, since I’m pretty new to this stuff, I’m powder shopping for my two. I realize the .17AB and .17FB are both relatively close-ish in performance, but the prices were right so I pounced. I was initially hoping for a .17 Hornet and a Fireball, but holy hell the going prices for anything Hornet are crazy these days! About the only rifles in mass production for it would be the Savage 25, which gets mixed reviews and sells for way too much for what it is IMO. Ruger and CZ are both put of the Hornet game, and both of them sell for STOOPID money most of the time. I still want one, but it may be awhile…

So anyway, the Ackley Bee will have to do in it’s stead. If anyone else is shooting these, I’m open to powder suggestions. Benchmark and 8208 both come recommended, but are both hard to find and expensive when you can find them. I’d prefer something relatively temp sensitive and less expensive, but that combo may be a unicorn right now. TAC, CFE-BLK, H335, and VV N120/130 are less expensive options that seem to get good reviews as well, so I may order a pound of each in a bit and start load development to see what I can get.

So, what’s everyone else shooting, if anything?

 

[Supersubes]

20 practical for the win! I just finished this one. I had hundreds of rounds left over from the previous krieger barrel, and fortunately this barrel shoots that load perfectly

My friends and I do high volume squirrel shooting. I think the 20’s are the sweet spot imo. Shot a lot of 17fb, but hated dicking with brass, which is shit quality.

My other rifle is a 20 fireball, which uses necked down Lapua .221 fb brass. Didn't want to mess with the 20 Vartarg because i didn't want to form cases.

 

[Birch7]

Accurate powders are generally available…not sure if they’re great for temps. Price is right, and usability overlaps a bit in speed range. 34 grains of 2460 got me to 4700 with my 20br shooting a 24gr ntx.

 

[Basher]

Accurate powders are generally available…not sure if they’re great for temps. Price is right, and usability overlaps a bit in speed range. 34 grains of 2460 got me to 4700 with my 20br shooting a 24gr ntx.

I’ll add them to my list of powders to check!

@Supersubes nice stick! The .20 Practical is the likely path I’ll take on the .20s. I see a LOT of guys rave about the .20VT, and I’m not opposed to forming brass (I’m going to have to with the .17AB), but being able to just neck down .223 brass down to .20 and go shoot seems highly appealing. I’m not familiar with the .20 Fireball so I may look at that as well.

Regarding .17FB brass, I’m going with Nosler as it’s the most readily available and generally gets better reviews than Remington brass. I’m also not against forming it from Lapua .221FB, but with that out of production at the moment, I’m not sure I want to pay the premium for it when I’m learning to form cases lol. I see lots of guys forming it from LC, which may be another option for me eventually. I’m so new to the .17s that I’m kind of willing to take the easy way out for most things at a slight price increase (as long as it’s reasonable) until I’m sure I want to stick with them and am willing to invest more time into things.

 

[SWgeezer]

I have a 17 fireball, a 17 mach IV, and a couple 204 Rugers, and a 20x6.8spc. Tac works great in the fireball sized rounds.

 

[cooper_257]

My boy loves his CZ 17 Ackley Hornet. With Accurate 2200 it can push a 20 grain Vmax around 3800.

 

[RFutch]

So I’m intrigued by the .20 cal stuff. Serious question though, what does it do for me that a 17HMR or 223 won’t? I already have both of those and not sure what a .20 cal does better?

 

[Supersubes]

So I’m intrigued by the .20 cal stuff. Serious question though, what does it do for me that a 17HMR or 223 won’t? I already have both of those and not sure what a .20 cal does better?

Depends on which 20 you're talking about. The Hmr is fun for the closer stuff, but aerobatics and explosions aren't really there. 20 Practical/204 ruger are in a class by themselves for explosiveness and airtime. .223 is the easy button of course, but if youre interested in specializing at all, you’ll get a little more out of the 20P/204 ruger. More like a 22-250, but without so much heat and recoil.

 

[Supersubes]

I’ll add them to my list of powders to check!

@Supersubes nice stick! The .20 Practical is the likely path I’ll take on the .20s. I see a LOT of guys rave about the .20VT, and I’m not opposed to forming brass (I’m going to have to with the .17AB), but being able to just neck down .223 brass down to .20 and go shoot seems highly appealing. I’m not familiar with the .20 Fireball so I may look at that as well.

Regarding .17FB brass, I’m going with Nosler as it’s the most readily available and generally gets better reviews than Remington brass. I’m also not against forming it from Lapua .221FB, but with that out of production at the moment, I’m not sure I want to pay the premium for it when I’m learning to form cases lol. I see lots of guys forming it from LC, which may be another option for me eventually. I’m so new to the .17s that I’m kind of willing to take the easy way out for most things at a slight price increase (as long as it’s reasonable) until I’m sure I want to stick with them and am willing to invest more time into things.

The 20 Fireball is just something I made. I drew it up and Manson made the reamer. Simple neck down to 20. 39 gr bk’s at 3300, or 32 gr at 3450(shortish barrels). ~18gr of H4198. A 20 vartarg is basically a 30 degree shoulder fireball case and formed in a sizing die. Trading some capacity for shoulder angle. Didn't seem worth it to me. Either route is a good one though. With a truck axle barrel, you can pretty much shoot continuously with them.


The nosler 17fb brass is definitely better. Dont even bother with remington unless youre in a pinch. The .17 fb is a the sweet spot for 17’s imo. I just want less wind drift and more explosions/aerobatics.


A real shame lapua cut the .221 brass. I bought a bunch of it before it dried up. Lasts for ever in a good chamber with reasonable loads.

 

[NWnewguy]

I’ve wanted to get a 20VT for a long time. Shot with an old timer on PDs a long time ago and he had a can on it. It was super quiet and had essentially zero recoil in the 14# rifle he had . Sipped powder and never heated up the barrel. PDs put on some acrobatic displays when he hooked up though, which was nearly every time out to about 300yds with some wind. Seems like a near Los cause now that Lapua and the folks at capstone or whatever the company that runs them these days quit making the FB brass. Maybe if enough people ask for it they’ll get another run going. Should already have the tooling done.

 

[Basher]

The brass doesn’t seem like a massive issue to me. Granted, I’ve never formed a Fireball case from a .223 case so I don’t know how difficult it is, but I DO know it can be done. If I get a hankering for Lapua brass, I’ll probably just buy some .223 and learn how to form from it. Buying it ready made would obviously be more appealing for the .221 shooters, but for us .17 and .20 folk, we’d still have to work it some either way, so…

 

[Supersubes]

The brass doesn’t seem like a massive issue to me. Granted, I’ve never formed a Fireball case from a .223 case so I don’t know how difficult it is, but I DO know it can be done. If I get a hankering for Lapua brass, I’ll probably just buy some .223 and learn how to form from it. Buying it ready made would obviously be more appealing for the .221 shooters, but for us .17 and .20 folk, we’d still have to work it some either way, so…

Almost all of my 17fb brass is remington. Took about 800 virgin cases to come up with 500 good ones. Something in their manufacturing process was thrashing the inside of the necks(picture a heavy but partial inside neck ream). I have a bunch of nosler but haven't used it much. If its working for you I wouldn't even think about forming it from .223 brass.

I’ve wanted to get a 20VT for a long time. Shot with an old timer on PDs a long time ago and he had a can on it. It was super quiet and had essentially zero recoil in the 14# rifle he had . Sipped powder and never heated up the barrel. PDs put on some acrobatic displays when he hooked up though, which was nearly every time out to about 300yds with some wind. Seems like a near Los cause now that Lapua and the folks at capstone or whatever the company that runs them these days quit making the FB brass. Maybe if enough people ask for it they’ll get another run going. Should already have the tooling done.

Varmint hunters are cheap . I think the lapua 221 brass was never very popular since the high volume guys chose domestic brass, even though it wont last nearly as long as Lapua and is more expensive in the end. Would love to see them bring it back.







Pics for the thread.

The Pink Panther. Howa Mini action with a 18” 2.5 contour Krieger, chambered in 20 fireball. Stock is a modified Boyd’s. Built this as a xmas present for my girl a few years ago.

20 fireball loaded with 32gr Varmigedons. 18.2gr of H4198 goes 3415 fps out of this barrel.

 

[Basher]

I haven’t started loading it yet, so I’m not sure how the Nosler will do, but I’m hopeful it’s as “good” as reports state in comparison to the R-P. I’d rather not form either, but will if I decide it’s worth it. That’ll be awhile regardless as I’m new enough to reloading that I only want to tackle one crazy project at a time, and forming .17AB from .218 Bee will probably be challenge enough. I haven’t even started that yet!

How’s your Howa Mini feed from the mags? I want to restock my .17FB (these cheap Nylon factory 700 stocks kinda suck lol), but everywhere I read says that mag feeding the short little Fireball cases is a gamble/headache, so I’ve limited my very preliminary search to BDL stocks. Doesn’t seem short action BDL options are plentiful, so I MAY try mag feeding it with something, but we’ll see.

 

[steve123]

I have always loved little cartridges!

Although there are guys out there with MUCH more experience with little cartridges than I have I've still played with a fair amount of them from 17 cal to 22 cal. It's a juggling act deciding which works like you prefer it too for the different situations you find yourself in.

I settled on this one called a 5mmFBI as my do all. Basically a 20VT AI with 40 degree shoulder. Although I can push it to 3850 fps with 32gr Vmax out of a 21" barrel it shoots better at 3750 fps.

Things I like compared to 17 cal;
Ease of putting powder and bullets into the cartridge case vs 17 cal, more energy on target, can make out misses easier at long range, more splat factor, higher BC, shoots like a 6mmPPC! Out of four 17's this 20 cal cartridge has been the most precise.
Long barrel life, barrel heats up slower, barrel doesn't need cleaning as much, 32 gr vmax is commonly found, only 18.8 grs of H4895 or 19.5gr CFE BlK, brass lasts a long time.

A 20 cal 32gr Vmax has almost the BC of a 22 cal 50gr Vmax so basically 22-250 ballistics if using the 50gr Vmax without some of the downsides of that cartridge.

A cool thing is I found a guy on Saubier that forms LC 5.56 brass to 20VT, sets the shoulder to my chamber, and turns the necks to my specs for $365 for 500 cases. The Remington brass I have now is at 7-8 cycles with mostly tight primer pockets but I think the LC brass will last twice what the Rem brass will.

Also I have a reduced load for plinking with 32gr Nosler HP at 2700 fps which is shown below.

 

[bodhisafa]

I like the idea of a 20 BR

 

[steve123]

I have a 20x47L/55's/.38BC at 3830 fps. Bullets started blowing up not even 300 rounds in. For whatever reason 40 grainers at 4100 fps work fine?? It's so fierce I haven't used that barrel in years. I could probably crank it up to 4300 fps but I'm not going there.

I'd definitely do a 20BR instead of 20x47L.

When I go to extremes I regret it later!

 

[Basher]

You bastards are gonna have me rebarreling my 700 from .17FB to .20VT or .20P lol. I’ve seen that guy on Saubier and I’ve been tempted to ask him if he can do .17FB brass, but now…

I don’t NEED two .17s, so we’ll see. The Ackley Bee and Fireball are pretty close in performance overall from what I hear, and the added advantages of a .20 would be nice.

I hate all of you now.

 

[Supersubes]

I haven’t started loading it yet, so I’m not sure how the Nosler will do, but I’m hopeful it’s as “good” as reports state in comparison to the R-P. I’d rather not form either, but will if I decide it’s worth it. That’ll be awhile regardless as I’m new enough to reloading that I only want to tackle one crazy project at a time, and forming .17AB from .218 Bee will probably be challenge enough. I haven’t even started that yet!

How’s your Howa Mini feed from the mags? I want to restock my .17FB (these cheap Nylon factory 700 stocks kinda suck lol), but everywhere I read says that mag feeding the short little Fireball cases is a gamble/headache, so I’ve limited my very preliminary search to BDL stocks. Doesn’t seem short action BDL options are plentiful, so I MAY try mag feeding it with something, but we’ll see.

The howa is sensitive to mag height. I had to set the bottom metal deeper into the stock to get the mag where I wanted it in relation to the action. Works good now.


So are you gonna shoot critters with yours, or just kill paper?

 

[Basher]

The howa is sensitive to mag height. I had to set the bottom metal deeper into the stock to get the mag where I wanted it in relation to the action. Works good now.


So are you gonna shoot critters with yours, or just kill paper?

Ah, well at least you got it to work! I’d be worried about hacking up a stock/chassis/DBM/mags only to find I couldn’t get it to work right and have to go back to square one anyway, so for now I think I’ll just start there. Damn few good R700 SA stocks cut for BDL setup being sold these days. I’d really like a Manners TA or T3 w/ the BDL mini chassis, but chances are I’ll have to save up and custom order one to get it…

I plan to “hunt” paper and critters with mine. The Ackley Bee is still on the way to me, but it’s a heavy Martini Cadet conversion, so I’m not likely to pack it around much. It will probably be mostly paper to start until I can figure out a good spot to hunt local vermin with it that affords me a few hundred yards with the option the set up a table or something.

The Fireball is a factory job that came to me in semi-meh shape. It has some light surface rust on the outside and the bore was pretty dirty with what looked like a touch of rust right at the bore end. It cleaned up OK without any obvious pitting, but for what I got it for, I consider everything outside the action itself to be a bonus I can sell for cheap and recoup a few bucks, then have a factory FB action to build off of. I have some factory ammo on the way to see how it does. If it doesn’t shoot amazingly well, I may consider cutting it back and recrowning to try again (it’s a 24” semi-sporter) or just saving up for a rebarrel in a slightly heavier contour. OR, I could keep the Ackley Bee as my only .17 and rebarrel to the .20VT or .20P. Gotta see how it shoots first, I guess!

 

[Supersubes]

Ah, well at least you got it to work! I’d be worried about hacking up a stock/chassis/DBM/mags only to find I couldn’t get it to work right and have to go back to square one anyway, so for now I think I’ll just start there. Damn few good R700 SA stocks cut for BDL setup being sold these days. I’d really like a Manners TA or T3 w/ the BDL mini chassis, but chances are I’ll have to save up and custom order one to get it…

I plan to “hunt” paper and critters with mine. The Ackley Bee is still on the way to me, but it’s a heavy Martini Cadet conversion, so I’m not likely to pack it around much. It will probably be mostly paper to start until I can figure out a good spot to hunt local vermin with it that affords me a few hundred yards with the option the set up a table or something.

The Fireball is a factory job that came to me in semi-meh shape. It has some light surface rust on the outside and the bore was pretty dirty with what looked like a touch of rust right at the bore end. It cleaned up OK without any obvious pitting, but for what I got it for, I consider everything outside the action itself to be a bonus I can sell for cheap and recoup a few bucks, then have a factory FB action to build off of. I have some factory ammo on the way to see how it does. If it doesn’t shoot amazingly well, I may consider cutting it back and recrowning to try again (it’s a 24” semi-sporter) or just saving up for a rebarrel in a slightly heavier contour. OR, I could keep the Ackley Bee as my only .17 and rebarrel to the .20VT or .20P. Gotta see how it shoots first, I guess!

Is the 17 fb a remington 700?

 

[Basher]

Is the 17 fb a remington 700?

It is, yes. Not sure on the model, it came in one of their super cheap polymer stocks w/ BDL bottom metal.

 

[Supersubes]

It is, yes. Not sure on the model, it came in one of their super cheap polymer stocks w/ BDL bottom metal.

The guts of that internal magazine are kinda hard to come by these days. You asked about detachable magazines earlier in regards to the howa. I’m going to see if a fireball case will feed from a magpul 223 AICS magazine in a r700 action. I’ll let you know how it goes.

 

[Basher]

I’m running a .17FB, so I’m not sure if that would somehow make a difference, but with my luck…

I suppose if I went with a chassis that allowed for me to adjust mag height (probably go with a Bravo because they’re inexpensive and easy to move if it doesn’t work), I could dicker with it and see if I could get it to work. As noted though, something tells me I’d need a spacer in the mag, which would mean altering a mag myself. It might be worth a shot, not sure yet though. Frankly, I’d be perfectly happy with a 5rnd BDL setup, but a 10rnd AICS would be the bees knees.

 

[cas6969]

I have a .17 Ackley Bee, but sadly I haven't shot it in probably fifteen years. I drifted away from my Contenders about that time (when it was finally legal to hunt deer with a rifle). Not long after that the field I got it to hunt chucks in stopped being cut/farmed so it lost it's job. I think about getting back to it now and again, but where I shoot seems to always be windy, knowing it would frustrate me a lot, I haevn't bothered.

 

[xphunter]

20 Vartarg

17 Mach IV

20 BR (8T) at a PRS match

 

[bodhisafa]

20 Vartarg

17 Mach IV

20 BR (8T) at a PRS match

How you like your 20 BR?

 

[xphunter]

Love it!
Shot it out beyond a grand on steel. Killed pd's and yotes with it.
And as noted, even shot a PRS match with it. Came in just a little bit better than halfway in the field.
55 Grain Berger's and Varget.
MV is 3173 fps

 

[shoots100]

I built a 20P turn bolt rifle years ago to test out the .20 cal waters and was very impressed.
After finding out that Savage wasn't making any .378" bolt heads for the Savage Impulse rifle for me to chamber it in 20P, I ended up building a
20-250.
No special mags needed, easy brass forming and the parent 22-250 brass is readily available.
It's been a great cartridge so far.

 

[Supersubes]

I built a 20P turn bolt rifle years ago to test out the .20 cal waters and was very impressed.
After finding out that Savage wasn't making any .378" bolt heads for the Savage Impulse rifle for me to chamber it in 20P, I ended up building a
20-250.
No special mags needed, easy brass forming and the parent 22-250 brass is readily available.
It's been a great cartridge so far.
View attachment 8107506View attachment 8107507

Whats the 20-250 load? How fast?

 

[RTH1800]

I shoot a .204, 20 tactical and 20-250.

 

[Franko]

If I could shoot prairie dogs or ground squirrels anywhere near me I would own a 20 practical. I still might build one as there is just something about shooting fast low recoiling cartridges...

 

[st1650]

204 Ruger with Berger 40 BT/ IMR XBR for me. Very accurate, no recoil and the wife can pop yotes off hand. I have mine on a anTI action with a MPA ultra lite chassis.

 

[shoots100]

Whats the 20-250 load? How fast?

I'm shooting a 55 gr berger /4350 load that the fellow I bought the barrel from said shot lights out and it does.
Haven't chrono'd the load, as I wanted to get out in the field to shoot coyotes with it before the NY season ended.
I bought some 40 gr NBT's and will see how fast I can push them accurately before chopping the barrel to make it lighter and easier to hump around.

SJC

 

[st1650]

Too bad Berger discontinued the 55gr 20cal. I would have loved doing a 20BR

 

[Supersubes]

Too bad Berger discontinued the 55gr 20cal. I would have loved doing a 20BR

The always seem to pop back up. They’re in stock at grafs now, and they have tens of thousands of them.

 

[supercorndogs]

Depends on which 20 you're talking about. The Hmr is fun for the closer stuff, but aerobatics and explosions aren't really there. 20 Practical/204 ruger are in a class by themselves for explosiveness and airtime. .223 is the easy button of course, but if youre interested in specializing at all, you’ll get a little more out of the 20P/204 ruger. More like a 22-250, but without so much heat and recoil.

Which bullet? So far the 34g Nolsers have been less than impressive. I have some 40 v-max and they have been better. I haven't shot many of them yet, but nothing I haven't seen from the 55,50, or 53 v-max, or the Seirra 55 HPBT in the 223.

 

[Supersubes]

Which bullet? So far the 34g Nolsers have been less than impressive. I have some 40 v-max and they have been better. I haven't shot many of them yet, but nothing I haven't seen from the 55,50, or 53 v-max, or the Seirra 55 HPBT in the 223.

Sierra blitzking, either 32 or 39.

 

[st1650]

Blitz king 39gr are great but I have had slightly better accuracy with the Berger 40. The Berger 40s have killed everything they’ve touched inside of 200 yards but I haven’t shot any yotes past that distance.

 

[Franko]

Too bad Berger discontinued the 55gr 20cal. I would have loved doing a 20BR

I have read a few places that Berger still makes the 55 grain projectiles but just for Grafs. Maybe it's true, maybe it isnt. The idea of a 20-223 or even a 20-223AI with an 8 twist barrel throwing those 55 grain projectiles is certainly interesting. However, it would really suck to put together a gun and find out your barrel didn't like the 55 grainers.

 

[xphunter]

In stock

BERGER 20(.204) 55gr HPBT BULLET (VARMINT) 100/bx - Graf & Sons

Exclusive to Grafs! After noticing an interest, Grafs contacted Berger for a special run of these varmint bullets. Get them while you can! Berger Long Range BT Varmint Bullets feature Match Grade quality construction and have a large hollow point that produces rapid expansion when used for...

www.grafs.com

Order the bullets for the life of the barrel, then, do the build - easy-peasy!

 

[Triggerf16]

I built a Tikka T3X repeater in 20VT off a 223 CTR action. CZ 527 magazines (221 fireball) inside a magazine holder which fits the Tikka mag well. Now it’s in a KRG Bravo. Works great with 1:11 twist and 32-40gr bullets and CFE223. Mags run well if you run the bolt quickly. If you run the bolt slowly, it will occasionally choke. Lapua 221 Fireball brass.

 

[steve123]

Sure wish Mike, formerly from Vudoo, would build that tiny centerfire action!!!!!!!!!!!!!!

 

[RTH1800]

Old thread but a good one.
I have 3 20 cal rifles.
.204
.20 Practical
20/250

Shot them extensively.

Easy button is the .204.

 

[Supersubes]

Old thread but a good one.
I have 3 20 cal rifles.
.204
.20 Practical
20/250

Shot them extensively.

Easy button is the .204.

What bullet do you shoot out of the 20/250? What powder, and how fast?

 

[supercorndogs]

Sierra blitzking, either 32 or 39.

Turns out I am only shooting the 40s 3400fps in my 20 practical. I will have to bump the powder charge up a couple notches. I actually have a different powder to try also. I need to prime some brass and load some ladders to get an idea of velocity.

 

[Stevo86]

The Calhoun 19 caliber stuff always intrigued me, but I’ve never pulled the trigger in building one. Need to look into it more seriously one day

 

[RTH1800]

I shoot 55 grain Bergers in the 20/250. 3400 or so iirc.

 

[RTH1800]

I really like the 32 grain bullet in the .204 and .20 Practical.
The 39-40 looks better on paper but the 32 simply works.

 

[Supersubes]

Turns out I am only shooting the 40s 3400fps in my 20 practical. I will have to bump the powder charge up a couple notches. I actually have a different powder to try also. I need to prime some brass and load some ladders to get an idea of velocity.

Turn that sucker up! How long a barrel? What powders?

 

[Supersubes]

I really like the 32 grain bullet in the .204 and .20 Practical.
The 39-40 looks better on paper but the 32 simply works.

The 32’s do work, for sure. When I cared enough to keep records, my hit percentages on squirrels went up a bit with 39’s. 300 yd paper groups were always a little larger in the horizontal with the 32’s. Minor overall, but picked the 39’s.